Wireless communication systems typically include base stations that are arranged to provide wireless communication service over a selected geographic region, for example. Base stations typically include an antenna and a base station transceiver (BTS). The operative components of the BTS typically include a DC-DC converter. A stability capacitor typically is placed in parallel with at least the DC-DC converter to provide stability in a known manner.
Introducing a stability capacitor provides the advantage of more reliable operation, however, there is a drawback. During start-up conditions, for example, the stability capacitor will cause an undesirably high current draw until the capacitor is fully charged, for example. In some instances, the current rush can be 200 times greater than the steady state current of the operative components of the BTS. Such a high current draw may damage some components and, at least, typically triggers a battery or other powering device shutdown.
To address that situation, the typical approach is to include a current limiting field effect transistor (FET) that throttles the current to the operative components during start up conditions. While this approach has proven useful, those skilled in the art are always striving to make improvements. For example, the arrangement of the FET in series with the capacitive stability device and the operative components requires the FET to be designed to accommodate the steady state current of the operative components during normal operation. This introduces additional cost into a BTS. Another issue presented by commonly used current limiting FETs is that they require heat sink capability to absorb heat generated during operation. Adding additional heat sink components adds further cost to a BTS.
It would be useful to have a new arrangement that does not have the added costs associated with typical current limiting FETs while still providing the current protection capability of known arrangements.